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From: diamond@tkou02.enet.dec.com (diamond@tkovoa)
Newsgroups: comp.std.c
Subject: Re: Multibyte character constants????
Keywords: Hackers of the world, unite!
Message-ID: <1824@tkou02.enet.dec.com>
Date: 29 Jun 90 03:59:16 GMT
References: <1990Jun28.221927.6823@idt.unit.no>
Reply-To: diamond@tkou02.enet.dec.com (diamond@tkovoa)
Organization: Digital Equipment Corporation Japan , Tokyo
Lines: 28

In article <1990Jun28.221927.6823@idt.unit.no> arnej@solan1.solan.unit.no writes:

>We have stumbled across the subject of multibyte character
>constants.  Is this defined anywhere?

Exactly the opposite.  The standard did not even just leave it undefined
by saying nothing.  The standard explicitly says that it's undefined.

>For example, if we say
>main(){printf("%d\n",'AB');}
>what should the output be?

It does not have to compile.  It does not have to execute.  It it does,
it can print anything, or exec rogue.

As a quality-of-implementation issue, a lot of vendors (as extensions)
define a meaning for it, and some of them even tell you what they have
defined.  You found some of them:
>We have used different compilers on different machines,
>and all but one gave the same answer: 'A'*256+'B'= 16706
>The odd one out was 'vcc', an ANSI complient compiler for
>ULTRIX. It gave 'B'*256+'A' = 16961.
But it would not be a good idea to depend on this behavior unless you
find a definition in the vendor's manual.  And you would not use it
at all in a portable program.
-- 
Norman Diamond, Nihon DEC     diamond@tkou02.enet.dec.com
This is me speaking.  If you want to hear the company speak, you need DECtalk.